button: qcom-pmic: Fix dereference of uninitialised pointer

The pointer 'label' is declared and later dereferenced without ever
having a value assigned to it. Add an assignment to this pointer so it
will be valid later when dereferenced.

This issue was found by Smatch.

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Reviewed-by: Casey Connolly <casey.connolly@linaro.org>
Link: https://lore.kernel.org/r/20250723-button-qcom-pmic-v1-1-9c317ac71167@linaro.org
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>

drivers/button/button-qcom-pmic.c

@@ -195,8 +195,9 @@ static int button_qcom_pmic_bind(struct udevice *parent)
 			continue;
 		}
 
+		label = ofnode_get_name(node);
 		ret = device_bind_driver_to_node(parent, "qcom_pwrkey",
-						 ofnode_get_name(node),
+						 label,
 						 node, &dev);
 		if (ret) {
 			printf("Failed to bind %s! %d\n", label, ret);